/*
* BUILD COMMAND:
* gcc -Wall -I/usr/local/ofed/include -O2 -o RDMA_RC_example -L/usr/local/ofed/lib64 -L/usr/local/ofed/lib -libverbs RDMA_RC_example.c
*
*/

/******************************************************************************
*
* RDMA Aware Networks Programming Example
*
* This code demonstrates how to perform the following operations using the 
* VPI Verbs API:
*
* Send
* Receive
* RDMA Read
* RDMA Write
*
*****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>
#include <inttypes.h>
#include <endian.h>
#include <byteswap.h>
#include <getopt.h>

#include <sys/time.h>
#include <arpa/inet.h>
#include <infiniband/verbs.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

#define MAX_POLL_CQ_TIMEOUT 2000
#define MSG "SEND operation "
#define RDMAMSGR "RDMA read operation "
#define RDMAMSGW "RDMA write operation"
#define MSG_SIZE (strlen(MSG) + 1)
#define MAX_STREAMS 10 // 默认流数量
#define BUFFER_SIZE_SENT (10) // 每条流的大小 10MB
#define BUFFER_SIZE (10 * 1024 * 1024)
#if __BYTE_ORDER == __LITTLE_ENDIAN
static inline uint64_t htonll(uint64_t x) { return bswap_64(x); }
static inline uint64_t ntohll(uint64_t x) { return bswap_64(x); }
#elif __BYTE_ORDER == __BIG_ENDIAN
static inline uint64_t htonll(uint64_t x) { return x; }
static inline uint64_t ntohll(uint64_t x) { return x; }
#else
#error __BYTE_ORDER is neither __LITTLE_ENDIAN nor __BIG_ENDIAN
#endif

struct config_t {
    const char *dev_name; /* IB device name */
    char *server_name;    /* server host name */
    u_int32_t tcp_ports[MAX_STREAMS]; /* server TCP ports */
    int ib_port;          /* local IB port to work with */
    int gid_idx;          /* gid index to use */
};

struct cm_con_data_t {
    uint64_t addr;   /* Buffer address */
    uint32_t rkey;   /* Remote key */
    uint32_t qp_num; /* QP number */
    uint16_t lid;    /* LID of the IB port */
    uint8_t gid[16]; /* gid */
} __attribute__((packed));

struct resources {
    struct ibv_device_attr device_attr; /* Device attributes */
    struct ibv_port_attr port_attr;      /* IB port attributes */
    struct cm_con_data_t remote_props[MAX_STREAMS]; /* values to connect to remote side */
    struct ibv_context *ib_ctx;           /* device handle */
    struct ibv_pd *pd;                     /* PD handle */
    struct ibv_cq *cq[MAX_STREAMS];        /* CQ handle */
    struct ibv_qp *qp[MAX_STREAMS];        /* QP handle */
    struct ibv_mr *mr[MAX_STREAMS];        /* MR handle for buffers */
    char *buf[MAX_STREAMS];                /* memory buffer pointers */
    int sock;                              /* TCP socket file descriptor */
};

struct config_t config = {
    NULL,  /* dev_name */
    NULL,  /* server_name */
    {19875, 19876, 19877, 19878, 19879, 19880, 19881, 19882, 19883, 19884}, /* tcp_ports */
    1,     /* ib_port */
    -1     /* gid_idx */
};

/******************************************************************************
* Function: sock_connect
* Connect a socket. 
******************************************************************************/
static int sock_connect(const char *servername, int port) {
    struct addrinfo *resolved_addr = NULL;
    struct addrinfo *iterator;
    char service[6];
    int sockfd = -1;
    int listenfd = 0;
    int tmp;

    struct addrinfo hints = {
        .ai_flags = AI_PASSIVE,
        .ai_family = AF_INET,
        .ai_socktype = SOCK_STREAM
    };

    if (sprintf(service, "%d", port) < 0)
        goto sock_connect_exit;

    sockfd = getaddrinfo(servername, service, &hints, &resolved_addr);
    if (sockfd < 0) {
        fprintf(stderr, "%s for %s:%d\n", gai_strerror(sockfd), servername, port);
        goto sock_connect_exit;
    }

    for (iterator = resolved_addr; iterator; iterator = iterator->ai_next) {
        sockfd = socket(iterator->ai_family, iterator->ai_socktype, iterator->ai_protocol);
        if (sockfd >= 0) {
            if (servername) {
                // Client mode
                if ((tmp = connect(sockfd, iterator->ai_addr, iterator->ai_addrlen))) {
                    fprintf(stdout, "failed connect \n");
                    close(sockfd);
                    sockfd = -1;
                }
            } else {
                // Server mode
                listenfd = sockfd;
                sockfd = -1;
                if (bind(listenfd, iterator->ai_addr, iterator->ai_addrlen))
                    goto sock_connect_exit;
                listen(listenfd, 1);
                sockfd = accept(listenfd, NULL, 0);
            }
        }
    }
sock_connect_exit:
    if (listenfd)
        close(listenfd);
    if (resolved_addr)
        freeaddrinfo(resolved_addr);
    if (sockfd < 0) {
        if (servername)
            fprintf(stderr, "Couldn't connect to %s:%d\n", servername, port);
        else {
            perror("server accept");
            fprintf(stderr, "accept() failed\n");
        }
    }
    return sockfd;
}

/******************************************************************************
* Function: poll_completion
* Poll the completion queue for a single event.
******************************************************************************/
static int poll_completion(struct resources *res, int stream_index) {
    struct ibv_wc wc;
    unsigned long start_time_msec;
    unsigned long cur_time_msec;
    struct timeval cur_time;
    int poll_result;
    int rc = 0;

    gettimeofday(&cur_time, NULL);
    start_time_msec = (cur_time.tv_sec * 1000) + (cur_time.tv_usec / 1000);
    do {
        poll_result = ibv_poll_cq(res->cq[stream_index], 1, &wc);
        gettimeofday(&cur_time, NULL);
        cur_time_msec = (cur_time.tv_sec * 1000) + (cur_time.tv_usec / 1000);
    } while ((poll_result == 0) && ((cur_time_msec - start_time_msec) < MAX_POLL_CQ_TIMEOUT));

    if (poll_result < 0) {
        fprintf(stderr, "poll CQ failed\n");
        rc = 1;
    } else if (poll_result == 0) {
        fprintf(stderr, "completion wasn't found in the CQ after timeout\n");
        rc = 1;
    } else {
        if (wc.status != IBV_WC_SUCCESS) {
            fprintf(stderr, "got bad completion with status: 0x%x, vendor syndrome: 0x%x\n", wc.status, wc.vendor_err);
            rc = 1;
        }
    }
    return rc;
}

/******************************************************************************
* Function: post_send
* Create and post a send work request
******************************************************************************/
static int post_send(struct resources *res, int opcode, int stream_index) {
    struct ibv_send_wr sr;
    struct ibv_sge sge;
    struct ibv_send_wr *bad_wr = NULL;
    int rc;

    memset(&sge, 0, sizeof(sge));
    sge.addr = (uintptr_t)res->buf[stream_index];
    if (opcode == IBV_WR_SEND) sge.length = BUFFER_SIZE_SENT; // 每条流的大小为10MB
    else sge.length = BUFFER_SIZE;
    sge.lkey = res->mr[stream_index]->lkey;

    memset(&sr, 0, sizeof(sr));
    sr.next = NULL;
    sr.wr_id = stream_index;
    sr.sg_list = &sge;
    sr.num_sge = 1;
    sr.opcode = opcode;//IBV_WR_SEND;
    sr.send_flags = IBV_SEND_SIGNALED;

    if (opcode != IBV_WR_SEND)
    {
	    sr.wr.rdma.remote_addr = res->remote_props[stream_index].addr;
	    sr.wr.rdma.rkey = res->remote_props[stream_index].rkey;
    }

    rc = ibv_post_send(res->qp[stream_index], &sr, &bad_wr);
    if (rc) {
        fprintf(stderr, "failed to post SR for stream %d\n", stream_index);
    } else {
        fprintf(stdout, "Send Request for stream %d was posted\n", stream_index);
    }
    return rc;
}

/******************************************************************************
* Function: resources_create
* Create and allocate all necessary system resources.
*****************************************************************************/
static int resources_create(struct resources *res) {
    struct ibv_device **dev_list = NULL;
    struct ibv_qp_init_attr qp_init_attr;
    struct ibv_device *ib_dev = NULL;
    size_t size;
    int i;
    int mr_flags = 0;
    int cq_size = 0;
    int num_devices;
    int rc = 0;

    if (config.server_name) {
        res->sock = sock_connect(config.server_name, config.tcp_ports[0]);
        if (res->sock < 0) {
            fprintf(stderr, "failed to establish TCP connection to server %s, port %d\n",
                    config.server_name, config.tcp_ports[0]);
            rc = -1;
            goto resources_create_exit;
        }
    } else {
        fprintf(stdout, "waiting on port %d for TCP connection\n", config.tcp_ports[0]);
        res->sock = sock_connect(NULL, config.tcp_ports[0]);
        if (res->sock < 0) {
            fprintf(stderr, "failed to establish TCP connection with client on port %d\n",
                    config.tcp_ports[0]);
            rc = -1;
            goto resources_create_exit;
        }
    }

    fprintf(stdout, "TCP connection was established\n");
    fprintf(stdout, "searching for IB devices in host\n");

    dev_list = ibv_get_device_list(&num_devices);
    if (!dev_list) {
        fprintf(stderr, "failed to get IB devices list\n");
        rc = 1;
        goto resources_create_exit;
    }

    if (!num_devices) {
        fprintf(stderr, "found %d device(s)\n", num_devices);
        rc = 1;
        goto resources_create_exit;
    }

    fprintf(stdout, "found %d device(s)\n", num_devices);
    for (i = 0; i < num_devices; i++) {
        if (!config.dev_name) {
            config.dev_name = strdup(ibv_get_device_name(dev_list[i]));
            fprintf(stdout, "device not specified, using first one found: %s\n", config.dev_name);
        }
        if (!strcmp(ibv_get_device_name(dev_list[i]), config.dev_name)) {
            ib_dev = dev_list[i];
            break;
        }
    }

    if (!ib_dev) {
        fprintf(stderr, "IB device %s wasn't found\n", config.dev_name);
        rc = 1;
        goto resources_create_exit;
    }

    res->ib_ctx = ibv_open_device(ib_dev);
    if (!res->ib_ctx) {
        fprintf(stderr, "failed to open device %s\n", config.dev_name);
        rc = 1;
        goto resources_create_exit;
    }

    ibv_free_device_list(dev_list);
    dev_list = NULL;
    ib_dev = NULL;

    if (ibv_query_port(res->ib_ctx, config.ib_port, &res->port_attr)) {
        fprintf(stderr, "ibv_query_port on port %u failed\n", config.ib_port);
        rc = 1;
        goto resources_create_exit;
    }

    res->pd = ibv_alloc_pd(res->ib_ctx);
    if (!res->pd) {
        fprintf(stderr, "ibv_alloc_pd failed\n");
        rc = 1;
        goto resources_create_exit;
    }

    for (i = 0; i < MAX_STREAMS; i++) {
        cq_size = 1; // 每条流使用一个CQ
        res->cq[i] = ibv_create_cq(res->ib_ctx, cq_size, NULL, NULL, 0);
        if (!res->cq[i]) {
            fprintf(stderr, "failed to create CQ with %u entries\n", cq_size);
            rc = 1;
            goto resources_create_exit;
        }

        res->buf[i] = (char *)malloc(BUFFER_SIZE);
        if (!res->buf[i]) {
            fprintf(stderr, "failed to malloc %Zu bytes to memory buffer\n", BUFFER_SIZE);
            rc = 1;
            goto resources_create_exit;
        }
        memset(res->buf[i], 0, BUFFER_SIZE);

        mr_flags = IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_READ | IBV_ACCESS_REMOTE_WRITE;
        res->mr[i] = ibv_reg_mr(res->pd, res->buf[i], BUFFER_SIZE, mr_flags);
        if (!res->mr[i]) {
            fprintf(stderr, "ibv_reg_mr failed with mr_flags=0x%x\n", mr_flags);
            rc = 1;
            goto resources_create_exit;
        }

        memset(&qp_init_attr, 0, sizeof(qp_init_attr));
        qp_init_attr.qp_type = IBV_QPT_RC;
        qp_init_attr.sq_sig_all = 1;
        qp_init_attr.send_cq = res->cq[i];
        qp_init_attr.recv_cq = res->cq[i];
        qp_init_attr.cap.max_send_wr = 1;
        qp_init_attr.cap.max_recv_wr = 1;
        qp_init_attr.cap.max_send_sge = 1;
        qp_init_attr.cap.max_recv_sge = 1;

        res->qp[i] = ibv_create_qp(res->pd, &qp_init_attr);
        if (!res->qp[i]) {
            fprintf(stderr, "failed to create QP\n");
            rc = 1;
            goto resources_create_exit;
        }
        fprintf(stdout, "QP %d was created, QP number=0x%x\n", i, res->qp[i]->qp_num);
    }

resources_create_exit:
    if (rc) {
        for (i = 0; i < MAX_STREAMS; i++) {
            if (res->qp[i]) {
                ibv_destroy_qp(res->qp[i]);
                res->qp[i] = NULL;
            }
            if (res->mr[i]) {
                ibv_dereg_mr(res->mr[i]);
                res->mr[i] = NULL;
            }
            if (res->buf[i]) {
                free(res->buf[i]);
                res->buf[i] = NULL;
            }
            if (res->cq[i]) {
                ibv_destroy_cq(res->cq[i]);
                res->cq[i] = NULL;
            }
        }
        if (res->pd) {
            ibv_dealloc_pd(res->pd);
            res->pd = NULL;
        }
        if (res->ib_ctx) {
            ibv_close_device(res->ib_ctx);
            res->ib_ctx = NULL;
        }
        if (res->sock >= 0) {
            close(res->sock);
            res->sock = -1;
        }
    }
    return rc;
}

/******************************************************************************
* Function: modify_qp_to_init
* Transition a QP from the RESET to INIT state
******************************************************************************/
static int modify_qp_to_init(struct ibv_qp *qp) {
    struct ibv_qp_attr attr;
    int flags;
    int rc;

    memset(&attr, 0, sizeof(attr));
    attr.qp_state = IBV_QPS_INIT;
    attr.port_num = config.ib_port;
    attr.pkey_index = 0;
    attr.qp_access_flags = IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_READ | IBV_ACCESS_REMOTE_WRITE;
    flags = IBV_QP_STATE | IBV_QP_PKEY_INDEX | IBV_QP_PORT | IBV_QP_ACCESS_FLAGS;

    rc = ibv_modify_qp(qp, &attr, flags);
    if (rc)
        fprintf(stderr, "failed to modify QP state to INIT\n");
    return rc;
}

/******************************************************************************
* Function: modify_qp_to_rtr
* Transition a QP from the INIT to RTR state
******************************************************************************/
static int modify_qp_to_rtr(struct ibv_qp *qp, uint32_t remote_qpn, uint16_t dlid, uint8_t *dgid) {
    struct ibv_qp_attr attr;
    int flags;
    int rc;

    memset(&attr, 0, sizeof(attr));
    attr.qp_state = IBV_QPS_RTR;
    attr.path_mtu = IBV_MTU_256;
    attr.dest_qp_num = remote_qpn;
    attr.rq_psn = 0;
    attr.max_dest_rd_atomic = 1;
    attr.min_rnr_timer = 0x12;
    attr.ah_attr.is_global = 0;
    attr.ah_attr.dlid = dlid;
    attr.ah_attr.sl = 0;
    attr.ah_attr.src_path_bits = 0;
    attr.ah_attr.port_num = config.ib_port;

    if (config.gid_idx >= 0) {
        attr.ah_attr.is_global = 1;
        attr.ah_attr.port_num = 1;
        memcpy(&attr.ah_attr.grh.dgid, dgid, 16);
        attr.ah_attr.grh.flow_label = 0;
        attr.ah_attr.grh.hop_limit = 1;
        attr.ah_attr.grh.sgid_index = config.gid_idx;
        attr.ah_attr.grh.traffic_class = 0;
    }

    flags = IBV_QP_STATE | IBV_QP_AV | IBV_QP_PATH_MTU | IBV_QP_DEST_QPN |
            IBV_QP_RQ_PSN | IBV_QP_MAX_DEST_RD_ATOMIC | IBV_QP_MIN_RNR_TIMER;

    rc = ibv_modify_qp(qp, &attr, flags);
    if (rc)
        fprintf(stderr, "failed to modify QP state to RTR\n");
    return rc;
}

/******************************************************************************
* Function: modify_qp_to_rts
* Transition a QP from the RTR to RTS state
******************************************************************************/
static int modify_qp_to_rts(struct ibv_qp *qp) {
    struct ibv_qp_attr attr;
    int flags;
    int rc;

    memset(&attr, 0, sizeof(attr));
    attr.qp_state = IBV_QPS_RTS;
    attr.timeout = 0x12;
    attr.retry_cnt = 6;
    attr.rnr_retry = 0;
    attr.sq_psn = 0;
    attr.max_rd_atomic = 1;

    flags = IBV_QP_STATE | IBV_QP_TIMEOUT | IBV_QP_RETRY_CNT |
            IBV_QP_RNR_RETRY | IBV_QP_SQ_PSN | IBV_QP_MAX_QP_RD_ATOMIC;

    rc = ibv_modify_qp(qp, &attr, flags);
    if (rc)
        fprintf(stderr, "failed to modify QP state to RTS\n");
    return rc;
}

static int post_receive(struct resources *res, int stream_index)
{
	struct ibv_recv_wr rr;
	struct ibv_sge sge;
	struct ibv_recv_wr *bad_wr;
	int rc;
	/* prepare the scatter/gather entry */
	memset(&sge, 0, sizeof(sge));
	sge.addr = (uintptr_t)(res->buf[stream_index]);
	sge.length = MSG_SIZE;
	sge.lkey = res->mr[stream_index]->lkey;
	/* prepare the receive work request */
	memset(&rr, 0, sizeof(rr));
	rr.next = NULL;
	rr.wr_id = 0;
	rr.sg_list = &sge;
	rr.num_sge = 1;
	/* post the Receive Request to the RQ */
	rc = ibv_post_recv(res->qp[stream_index], &rr, &bad_wr);
	if (rc)
		fprintf(stderr, "failed to post RR\n");
	else
		fprintf(stdout, "Receive Request was posted\n");
	return rc;
}

int sock_sync_data(int sock, int xfer_size, char *local_data, char *remote_data)
{
	int rc;
	int read_bytes = 0;
	int total_read_bytes = 0;
	rc = write(sock, local_data, xfer_size);
	if (rc < xfer_size)
		fprintf(stderr, "Failed writing data during sock_sync_data\n");
	else
		rc = 0;
	while (!rc && total_read_bytes < xfer_size)
	{
		read_bytes = read(sock, remote_data, xfer_size);
		if (read_bytes > 0)
			total_read_bytes += read_bytes;
		else
			rc = read_bytes;
	}
	return rc;
}

/******************************************************************************
* Function: connect_qp
* Connect the QP. Transition the server side to RTR, sender side to RTS
******************************************************************************/
static int connect_qp(struct resources *res, int stream_index) {
    struct cm_con_data_t local_con_data;
    struct cm_con_data_t remote_con_data;
    struct cm_con_data_t tmp_con_data;
    int rc = 0;
    char temp_char;
    union ibv_gid my_gid;

    if (config.gid_idx >= 0) {
        rc = ibv_query_gid(res->ib_ctx, config.ib_port, config.gid_idx, &my_gid);
        if (rc) {
            fprintf(stderr, "could not get gid for port %d, index %d\n", config.ib_port, config.gid_idx);
            return rc;
        }
    } else {
        memset(&my_gid, 0, sizeof my_gid);
    }

    local_con_data.addr = htonll((uintptr_t)res->buf[stream_index]);
    local_con_data.rkey = htonl(res->mr[stream_index]->rkey);
    local_con_data.qp_num = htonl(res->qp[stream_index]->qp_num);
    local_con_data.lid = htons(res->port_attr.lid);
    memcpy(local_con_data.gid, &my_gid, 16);
    fprintf(stdout, "\nLocal LID = 0x%x\n", res->port_attr.lid);

    if (sock_sync_data(res->sock, sizeof(struct cm_con_data_t), (char *)&local_con_data, (char *)&tmp_con_data) < 0) {
        fprintf(stderr, "failed to exchange connection data between sides\n");
        rc = 1;
        goto connect_qp_exit;
    }

    remote_con_data.addr = ntohll(tmp_con_data.addr);
    remote_con_data.rkey = ntohl(tmp_con_data.rkey);
    remote_con_data.qp_num = ntohl(tmp_con_data.qp_num);
    remote_con_data.lid = ntohs(tmp_con_data.lid);
    memcpy(remote_con_data.gid, tmp_con_data.gid, 16);
    res->remote_props[stream_index] = remote_con_data;

    fprintf(stdout, "start modifying qo state\n");

    rc = modify_qp_to_init(res->qp[stream_index]);
    if (rc) {
        fprintf(stderr, "change QP state to INIT failed\n");
        goto connect_qp_exit;
    }


    if (config.server_name) {
        rc = post_receive(res, stream_index);
        if (rc) {
            fprintf(stderr, "failed to post RR\n");
            goto connect_qp_exit;
        }
    }


    rc = modify_qp_to_rtr(res->qp[stream_index], remote_con_data.qp_num, remote_con_data.lid, remote_con_data.gid);
    if (rc) {
        fprintf(stderr, "failed to modify QP state to RTR\n");
        goto connect_qp_exit;
    }


    rc = modify_qp_to_rts(res->qp[stream_index]);
    if (rc) {
        fprintf(stderr, "failed to modify QP state to RTS\n");
        goto connect_qp_exit;
    }

    fprintf(stdout, "QP state was change to RTS\n");

    if (sock_sync_data(res->sock, 1, "Q", &temp_char)) {
        fprintf(stderr, "sync error after QPs are were moved to RTS\n");
        rc = 1;
    }

connect_qp_exit:
    return rc;
}

/******************************************************************************
* Function: resources_destroy
* Cleanup and deallocate all resources used
******************************************************************************/
static int resources_destroy(struct resources *res) {
    int rc = 0;

    for (int i = 0; i < MAX_STREAMS; i++) {
        if (res->qp[i]) {
            if (ibv_destroy_qp(res->qp[i])) {
                fprintf(stderr, "failed to destroy QP\n");
                rc = 1;
            }
        }
        if (res->mr[i]) {
            if (ibv_dereg_mr(res->mr[i])) {
                fprintf(stderr, "failed to deregister MR\n");
                rc = 1;
            }
        }
        if (res->buf[i]) {
            free(res->buf[i]);
        }
        if (res->cq[i]) {
            if (ibv_destroy_cq(res->cq[i])) {
                fprintf(stderr, "failed to destroy CQ\n");
                rc = 1;
            }
        }
    }

    if (res->pd) {
        if (ibv_dealloc_pd(res->pd)) {
            fprintf(stderr, "failed to deallocate PD\n");
            rc = 1;
        }
    }
    if (res->ib_ctx) {
        if (ibv_close_device(res->ib_ctx)) {
            fprintf(stderr, "failed to close device context\n");
            rc = 1;
        }
    }
    if (res->sock >= 0) {
        if (close(res->sock)) {
            fprintf(stderr, "failed to close socket\n");
            rc = 1;
        }
    }
    return rc;
}

/******************************************************************************
* Function: print_config
* Print out config information
******************************************************************************/
static void print_config(void) {
    fprintf(stdout, " ------------------------------------------------\n");
    fprintf(stdout, " Device name : \"%s\"\n", config.dev_name);
    fprintf(stdout, " IB port : %u\n", config.ib_port);
    if (config.server_name)
        fprintf(stdout, " IP : %s\n", config.server_name);
    for (int i = 0; i < MAX_STREAMS; i++) {
        fprintf(stdout, " TCP port %d : %u\n", i, config.tcp_ports[i]);
    }
    if (config.gid_idx >= 0)
        fprintf(stdout, " GID index : %u\n", config.gid_idx);
    fprintf(stdout, " ------------------------------------------------\n\n");
}

/******************************************************************************
* Function: usage
* print a description of command line syntax
******************************************************************************/
static void usage(const char *argv0) {
    fprintf(stdout, "Usage:\n");
    fprintf(stdout, " %s start a server and wait for connection\n", argv0);
    fprintf(stdout, " %s <host> connect to server at <host>\n", argv0);
    fprintf(stdout, "\n");
    fprintf(stdout, "Options:\n");
    fprintf(stdout, " -p, --port <port> listen on/connect to port <port> (default 18515)\n");
    fprintf(stdout, " -d, --ib-dev <dev> use IB device <dev> (default first device found)\n");
    fprintf(stdout, " -i, --ib-port <port> use port <port> of IB device (default 1)\n");
    fprintf(stdout, " -g, --gid_idx <git index> gid index to be used in GRH (default not used)\n");
}

/******************************************************************************
* Function: main
* Main program code
******************************************************************************/
int main(int argc, char *argv[]) {
    struct resources res;
    int rc = 1;
    char temp_char;

    // parse the command line parameters
    while (1) {
        int c;
        static struct option long_options[] = {
            { .name = "port", .has_arg = 1, .val = 'p' },
            { .name = "ib-dev", .has_arg = 1, .val = 'd' },
            { .name = "ib-port", .has_arg = 1, .val = 'i' },
            { .name = "gid-idx", .has_arg = 1, .val = 'g' },
            { .name = NULL, .has_arg = 0, .val = '\0' }
        };
        c = getopt_long(argc, argv, "p:d:i:g:", long_options, NULL);
        if (c == -1)
            break;
        switch (c) {
            case 'p':
                for (int i = 0; i < MAX_STREAMS; i++) {
                    config.tcp_ports[i] = strtoul(optarg, NULL, 0) + i; // 每条流使用不同的端口
                }
                break;
            case 'd':
                config.dev_name = strdup(optarg);
                break;
            case 'i':
                config.ib_port = strtoul(optarg, NULL, 0);
                if (config.ib_port < 0) {
                    usage(argv[0]);
                    return 1;
                }
                break;
            case 'g':
                config.gid_idx = strtoul(optarg, NULL, 0);
                if (config.gid_idx < 0) {
                    usage(argv[0]);
                    return 1;
                }
                break;
            default:
                usage(argv[0]);
                return 1;
        }
    }

    // parse the last parameter (if exists) as the server name
    if (optind == argc - 1)
        config.server_name = argv[optind];
    if (config.server_name) {
        printf("servername=%s\n", config.server_name);
    } else if (optind < argc) {
        usage(argv[0]);
        return 1;
    }

    // print the used parameters for info
    print_config();

    // init all of the resources, so cleanup will be easy
    memset(&res, 0, sizeof(res));
    res.sock = -1;

    // create resources before using them
    if (resources_create(&res)) {
        fprintf(stderr, "failed to create resources\n");
        goto main_exit;
    }

    fprintf(stdout, "resource created\n");

    // connect the QPs
    for (int i = 0; i < MAX_STREAMS; i++) {
        if (connect_qp(&res, i)) {
            fprintf(stderr, "failed to connect QPs\n");
            goto main_exit;
        }
    }

    // let the server post the send requests
    if (!config.server_name) {
        for (int i = 0; i < MAX_STREAMS; i++) {
            if (post_send(&res, IBV_WR_SEND, i)) {
                fprintf(stderr, "failed to post sr\n");
                goto main_exit;
            }
        }
    }

    // in both sides we expect to get a completion
    for (int i = 0; i < MAX_STREAMS; i++) {
        if (poll_completion(&res, i)) {
            fprintf(stderr, "poll completion failed\n");
            goto main_exit;
        }
    }

    // after polling the completion we have the message in the client buffer too
    if (config.server_name) {
        fprintf(stdout, "Received messages:\n");
        for (int i = 0; i < MAX_STREAMS; i++) {
            fprintf(stdout, "Buffer %d: '%s'\n", i, res.buf[i]);
        }
    } else {
        // setup server buffer with read message
        for (int i = 0; i < MAX_STREAMS; i++) {
            strcpy(res.buf[i], RDMAMSGR);
        }
    }

    // Sync so we are sure server side has data ready before client tries to read it
    if (sock_sync_data(res.sock, 1, "R", &temp_char)) { // just send a dummy char back and forth
        fprintf(stderr, "sync error before RDMA ops\n");
        rc = 1;
        goto main_exit;
    }

    // Now the client performs an RDMA read and then write on server.
    if (config.server_name) {
        // First we read contents of server's buffer
        for (int i = 0; i < MAX_STREAMS; i++) {
            if (post_send(&res, IBV_WR_RDMA_READ, i)) {
                fprintf(stderr, "failed to post SR 2\n");
                rc = 1;
                goto main_exit;
            }
            if (poll_completion(&res, i)) {
                fprintf(stderr, "poll completion failed 2\n");
                rc = 1;
                goto main_exit;
            }
            fprintf(stdout, "Contents of server's buffer for stream %d: '%s'\n", i, res.buf[i]);
        }

        // Now we replace what's in the server's buffer
        for (int i = 0; i < MAX_STREAMS; i++) {
            strcpy(res.buf[i], RDMAMSGW);
            fprintf(stdout, "Now replacing it with: '%s'\n", res.buf[i]);
            if (post_send(&res, IBV_WR_RDMA_WRITE, i)) {
                fprintf(stderr, "failed to post SR 3\n");
                rc = 1;
                goto main_exit;
            }
            if (poll_completion(&res, i)) {
                fprintf(stderr, "poll completion failed 3\n");
                rc = 1;
                goto main_exit;
            }
        }
    }

    // Sync so server will know that client is done mucking with its memory
    if (sock_sync_data(res.sock, 1, "W", &temp_char)) { // just send a dummy char back and forth
        fprintf(stderr, "sync error after RDMA ops\n");
        rc = 1;
        goto main_exit;
    }

    if (!config.server_name) {
        fprintf(stdout, "Contents of server buffer after writing:\n");
        for (int i = 0; i < MAX_STREAMS; i++) {
            fprintf(stdout, "Buffer %d: '%s'\n", i, res.buf[i]);
        }
    }

    rc = 0; // Success

main_exit:
    if (resources_destroy(&res)) {
        fprintf(stderr, "failed to destroy resources\n");
        rc = 1;
    }
    if (config.dev_name)
        free((char *)config.dev_name);
    fprintf(stdout, "\ntest result is %d\n", rc);
    return rc;
}
